Correct rotation angle for StsStation. Provide radiation length of silicon...

Correct rotation angle for StsStation. Provide radiation length of silicon from StsStation. Refs #133 @2h.

git-svn-id: https://subversion.gsi.de/cbmsoft/cbmroot/trunk@7584 5a1b234a-d7ce-0410-9a93-fd649a8fa65c

sts/setup/CbmStsSetup.cxx

@@ -258,7 +258,7 @@ Bool_t CbmStsSetup::Init(TGeoManager* geo) {
 	LOG(INFO) << GetName() << ": Set types for " << nSensors
 			      << " sensors" << FairLogger::endl;
 
-  // --- Init the stations (get station-wide parameters like z, xmax etc.)
+  // --- Initialise stations parameters
   for (Int_t iStat = 0; iStat < GetNofDaughters(); iStat++) {
   	CbmStsStation* station =
   			dynamic_cast<CbmStsStation*>(GetDaughter(iStat));

sts/setup/CbmStsStation.cxx

@@ -3,6 +3,7 @@
  ** @date 04.03.2015
  **/
 
+#include <cassert>
 #include <sstream>
 #include "TGeoBBox.h"
 #include "TGeoMatrix.h"
@@ -15,7 +16,7 @@
 CbmStsStation::CbmStsStation()
 	: CbmStsElement(),
 	  fZ(0.),
-	  fXmin(0.), fXmax(0.), fYmin(0.), fYmax(0.), fSensorD(0.),
+	  fXmin(0.), fXmax(0.), fYmin(0.), fYmax(0.), fSensorD(0.), fSensorRot(0.),
 	  fNofSensors(0),
 	  fDiffSensorD(kFALSE),
 	  fFirstSensor(NULL)
@@ -30,7 +31,7 @@ CbmStsStation::CbmStsStation(const char* name, const char* title,
 		                                 TGeoPhysicalNode* node)
 	: CbmStsElement(name, title, kStsStation, node),
 	  fZ(0.),
-    fXmin(0.), fXmax(0.), fYmin(0.), fYmax(0.), fSensorD(0.),
+    fXmin(0.), fXmax(0.), fYmin(0.), fYmax(0.), fSensorD(0.), fSensorRot(0.),
     fNofSensors(0),
     fDiffSensorD(kFALSE),
 		fFirstSensor(NULL)
@@ -131,20 +132,6 @@ Double_t CbmStsStation::GetSensorPitch(Int_t iSide) const {
 
 
 
-// -----   Rotation    -----------------------------------------------------
-// N.B.: Implementation is only correct if the first sensor is only rotated
-// in the x-y plane.
-Double_t CbmStsStation::GetSensorRotation() const {
-	TGeoPhysicalNode* sensorNode = fFirstSensor->GetNode();
-	Double_t local[3] = {1., 0., 0.}; // unit vector on local x axis
-	Double_t global[3];    // unit vector in global C.S.
-	sensorNode->GetMatrix()->LocalToMaster(local, global);
-	return atan2(global[1], global[0]); // angle from global to local x-axis
-}
-// -------------------------------------------------------------------------
-
-
-
 // -----   Stereo angle    -------------------------------------------------
 Double_t CbmStsStation::GetSensorStereoAngle(Int_t iSide) const {
 	if ( iSide < 0 || iSide > 1 ) {
@@ -188,6 +175,23 @@ void CbmStsStation::Init() {
 	if ( fDiffSensorD )
 		LOG(WARNING) << GetName() << ": Different values for sensor thickness!"
 		             << FairLogger::endl;
+
+	// Determine the rotation (in x-y) of the first sensor
+	assert(fFirstSensor);
+	TGeoPhysicalNode* sensorNode = fFirstSensor->GetNode();
+	assert(sensorNode);
+	// Transform unit vector on local x axis into global c.s.
+	Double_t unitLocal[3] = {1., 0., 0.};
+	Double_t unitGlobal[3];
+	sensorNode->GetMatrix()->LocalToMaster(unitLocal, unitGlobal);
+	// Subtract translation vector of local origin
+	Double_t* translation = sensorNode->GetMatrix()->GetTranslation();
+	unitGlobal[0] -= translation[0];
+	unitGlobal[1] -= translation[1];
+	unitGlobal[2] -= translation[2];
+	// Calculate angle between unit x vector in global and local c.s.
+	fSensorRot = atan2(unitGlobal[1], unitGlobal[0]);
+
 }
 // --------------------------------------------------------------------------
 
@@ -200,7 +204,8 @@ string CbmStsStation::ToString() const
    ss << GetName() << ": " << fNofSensors << " sensors, z = " << fZ
   	  << " cm, x = " << fXmin << " to " << fXmax << " cm, y = " << fYmin
   	  << " to " << fYmax << " cm " << "\n\t\t"
-  	  << " sensor thickness " << fSensorD << " cm"
+  	  << " rotation " << fSensorRot * 180. / 3.1415927 << " degrees,"
+  	  << " sensor thickness " << fSensorD << " cm,"
   	  << " pitch " << GetSensorPitch(0) << " cm / " << GetSensorPitch(1)
   	  << " cm, stereo angle " << GetSensorStereoAngle(0) << " / "
   	  << GetSensorStereoAngle(1);

sts/setup/CbmStsStation.h

@@ -40,11 +40,14 @@ class CbmStsStation : public CbmStsElement {
 		virtual ~CbmStsStation();
 
 
-		/** Minimal and maximal x and y coordinates **/
-		Double_t GetXmin() const { return fXmin; }
-		Double_t GetXmax() const { return fXmax; }
-		Double_t GetYmin() const { return fYmin; }
-		Double_t GetYmax() const { return fYmax; }
+
+		/** Radiation length of the main material of the station (silicon)
+		 ** @value  Radiation length of silicon [cm]
+		 **
+		 ** Required from L1/KF. The value for silicon is hard-coded here,
+		 ** since it is not likely that the material will change.
+		 **/
+		Double_t GetRadLength() const { return 9.34953; }
 
 
 		/** Sensor thickness
@@ -72,6 +75,18 @@ class CbmStsStation : public CbmStsElement {
 		Double_t GetSensorPitch(Int_t iSide) const;
 
 
+		/** Sensor rotation
+		 ** @value Rotation of first sensor in station in global C.S. [rad]
+		 **
+     ** This return the rotation angle in the x-y plane of the first sensor
+     ** in the station w.r.t. the global C.S.
+		 ** Needed by L1/KF.
+		 ** Note that in general, the rotation angle will be different for each
+		 ** sensor. In particular, half of them are upside down.
+		 **/
+		Double_t GetSensorRotation() const { return fSensorRot; }
+
+
 		/** Get sensor stereo angle
 		 ** @param iSide  Sensor side (0 = front, 1 = back)
 		 ** @value Stereo angle [degrees]
@@ -85,18 +100,11 @@ class CbmStsStation : public CbmStsElement {
 		Double_t GetSensorStereoAngle(Int_t iSide) const;
 
 
-
-		/** Sensor rotation
-		 ** @value Rotation of first sensor in station in global C.S. [rad]
-		 **
-     ** This return the rotation angle in the x-y plane of the first sensor
-     ** in the station w.r.t. the global C.S.
-		 ** Needed by L1/KF.
-		 ** Note that in general, the rotation angle will be different for each
-		 ** sensor. In particular, half of the are upside down.
-		 **/
-		Double_t GetSensorRotation() const;
-
+		/** Minimal and maximal x and y coordinates **/
+		Double_t GetXmin() const { return fXmin; }
+		Double_t GetXmax() const { return fXmax; }
+		Double_t GetYmin() const { return fYmin; }
+		Double_t GetYmax() const { return fYmax; }
 
 
 		/** Station z position in global c.s.
@@ -119,14 +127,15 @@ class CbmStsStation : public CbmStsElement {
 
 	private:
 
-		Double_t fZ;          ///< z position of station [cm]
-		Double_t fXmin;       ///< minimal x coordinate [cm]
-		Double_t fXmax;       ///< maximal x coordinate [cm]
-		Double_t fYmin;       ///< minimal y coordinate [cm]
-		Double_t fYmax;       ///< maximal y coordinate [cm]
-		Double_t fSensorD;    ///< thickness of sensors [cm]
-		Int_t    fNofSensors; ///< Number of sensors in station
-		Bool_t fDiffSensorD;  ///< Flag for different sensor thicknesses
+		Double_t fZ;            ///< z position of station [cm]
+		Double_t fXmin;         ///< minimal x coordinate [cm]
+		Double_t fXmax;         ///< maximal x coordinate [cm]
+		Double_t fYmin;         ///< minimal y coordinate [cm]
+		Double_t fYmax;         ///< maximal y coordinate [cm]
+		Double_t fSensorD;      ///< thickness of sensors [cm]
+		Double_t fSensorRot;    ///< Rotation of first sensor in global c.s. [rad]
+		Int_t    fNofSensors;   ///< Number of sensors in station
+		Bool_t   fDiffSensorD;  ///< Flag for different sensor thicknesses
 		CbmStsSensor* fFirstSensor; ///< Pointer to first sensor